S2/X1 and its taglib is oriented towards OGNL, which is using a value stack
for all action properties. These values are not direct available for the
expression language of JSP2/JSTL1.1.

However, it's easy to populate the request
attribute set, with all gettable properties of an action object. You need to provide
an interceptor that does the job, by register a PreResultListener which is
invoked after the return of Action.execute() but before the rendering of the result .

The interceptor below is using Jakarta BeanUtils. It first extracts all getters
of the current action, invokes them one at the time and stores the values into a map.
Then it iterates over the map and populates the request attribute set.The double iteration is not needed, it's just there for clarity.